Comment on Comments WordPress SEO Plugin by SEO Dave.
The WordPress SEO Comments Plugins grabs the latest 5 comments that match the authors email address.
Without seeing a URL only thing that comes to mind is you have multiple authors using the same email address?
In the version of the SEO comments plugin that’s part of the SEO package I develop I don’t include as many extra comments at the bottom, have 5 excerpts of the authors recent comments and have a bunch of additional SEO features built in.
See the output by clicking the link to the right of this comment with anchor text “WordPress Recent Comments by Author”.